The name is a reference to the hot 'dog days' of late summer when this species is heard singing. Mostly black with green markings on its body. The body size is typically 27 to 33 millimeters, the wingspan can reach 82 mm. The wings are interlaced with green veins which are especially noticeable near the base. The song of T. canicularis is often described as being a loud, high-pitched whine much like a power saw cutting wood. It lasts for several seconds before fading away at the end of the noise.
Common habitats are mixed and deciduous woods.